Methyl leucotylate

Two new hopanes, methyl pyxinate (172) and the corresponding acetate (173), occurin the lichen Pyxine endochrysina along with several dammaranes. Full papers have appeared on the structure of leucotylic acid (174) and on the correlation of zeorin (175) with leucotylin (176). On treatment with acid, methyl leucotylate (177) and leucotylin (176) afford methyl isoleucotylate (178) and isoleucotylin (179), respectively. 

Deriv Methyl leucotylate, plates (EtOH), mp 298-301 °C, [a]o + 29 (CHCI3, c 2.0), from leucotylic acid in EtOH with CHjNj at 5 °C in 1 day... 

Yosioka I, Nakanishi T, Yamaki M, Kitagawa I (1972b) Lichen triterpenoids. IV. The structures of leucotylic acid and methyl isoleucotylate, an acid-induced isomer of methyl leucotylate. Chem Pharm Bull 20 487-501... 

The acid catalysed epimerization of the C-21 group of leucotylin (482), to give isoleucotylin (483) in addition to leucotylidiene (484) has been reported 342) (Scheme 65). Methyl leucotylate is known to react in a similar manner 343, 341). 

Yosioka, I., T. Nakanishi, M. Yamaki, and I. Kitagawa The Structures of Leucotylic Acid and Methyl Isoleucotylate, an Acid-Induced Isomer of Methyl Leucotylate. Chem. Pharm. Bull. (Japan) 20, 487 (1972). 

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See also in sourсe #XX -- [ ]

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